Those familiar with timber harvesting are familiar with feller bunchers, such as the 900K-Series feller buncher manufactured and sold by John Deere. Feller bunchers are utilized to rapidly harvest trees using a boom to reposition a felling head. Typical felling heads have a large disc saw that is used to cut the base of a tree, while repositionable arms of the felling head are used to grasp the stem of the tree as the tree is being cut. While the tree is being cut and after the tree is severed from its base, it continues to be grasped by the felling head arms and rides upon a butt plate. The operator of the feller buncher then tilts the felling head and allows gravity to lay the tree down.
While laying down the cut tree, the feller head and boom may be subjected to kick-back or rebound forces as the tree bounces on the ground. These rebound forces are absorbed by components of the feller buncher's hydraulic system, namely the hydraulic cylinders associated with the feller head and boom. More specifically, the rebound forces applied to the hydraulic cylinders result in rapid hydraulic pressure increases within the cylinders, sometimes resulting in cylinder failure. While one alternative would be incorporation of larger, more robust hydraulic cylinders, this incorporation has ripple effects that require many other components such as the hydraulic pump and hoses to be more robust and substantially less efficient. Additional issues are also encountered such as, without limitation, additional weight and potential redesign of the feller head and feller boom to withstand the increased forces that can be transmitted by more robust hydraulic cylinders. Consequently, there is a need for a solution to account for rebound forces that may be applied to the feller buncher's hydraulic system without requiring a complete redesign of the hydraulic system or the equipment (feller head and boom) repositioned by the hydraulic system.